Species Extinction Rising, UT Prof Says In Science

KNOXVILLE, Tenn.– The current rate of species extinction is much higher than any other period in human existence and is escalating rapidly, a team of University of Tennessee researchers say in the current issue of Science magazine.

Estimates from a UT-Knoxville study predict the rate of species extinction to be 1,000 times higher than it was before humans appeared on Earth, the magazine reports.

Dr. Stuart Pimm, a UT-Knoxville zoologist and co-author of the report, said the rate will probably multiply by 10 times over the next 100 years.

Pimm said the extinctions are the result of habitat loss, accidental or deliberate introduction of other species, natural population fluctuations, and other causes.

The future rate of extinction is going to be much higher than now because so many species already are teetering on the brink of extinction, Pimm said.

“For example, we are currently losing one or two species of birds per year,” Pimm said, “but if you look at how many species are threatened with extinction, it looks as if we’ll lose about 1,000 species within the next 100 years. We think the rate will go up to 10 or maybe 20 species annually by then.”

Estimates were derived using data from fossil records of a wide variety of species, taxonomists’ records of current numbers of existing species, satellite imagery and other sources, Pimm said.

Pimm said the rising extinction rate will reduce the supply of many beneficial species used for drug manufacturing, medicine, agriculture and other purposes.

“These extinctions matter to us in a number of economic ways,” Pimm said.

Pimm testified last week before the U.S. Senate’s environmental subcommittee on reauthorization of the Endangered Species Act. Without the act, many species could be wiped out because they could lose their classification as an endangered species within two years, he said.

Dr. John Gittleman, a UT zoologist, and UT graduate teaching assistants Gareth Russell and Thomas Brooks also worked on the Science report.

Science is the weekly journal of the American Association for the Advancement of Science.